1. Field of the Invention
This invention relates to a device for the fastening of attachment elements, such as mounting rails, mounting plates, deposit plates and the like on a frame leg of a switchgear cabinet rack, wherein the frame legs are designed symmetrically in relation to their cross-sectional diagonal line and are aligned with their cross-sectional diagonal lines with the diagonal line of the rack. On the inside of the frame legs oriented toward the interior of the rack, the frame legs comprise a fastening receiver with two fastening profile sides which are disposed vertically in respect to each other and extend parallel to the facing outsides of the switchgear cabinet rack. The frame legs form system fastening receivers in the form of square or rectangular openings and fastening bores and make transitions into additional profile sides having corresponding rows of fastening receivers, which extend perpendicularly with the facing exteriors of the switchgear cabinet rack. The fastening elements can be connected to the frame legs, which have fastening faces with fastening receivers in three directions respectively extending at right angles to each other.
2. Description of Prior Art
A device of this type is known from German Patent Publication DE 195 37 016 C1 which teaches a switchgear cabinet rack assembled from frame legs which are embodied mirror-reversed, i.e. symmetrically, in respect to their cross-sectional diagonal line, and are oriented with their cross-sectional diagonal lines on the diagonal line of the switchgear cabinet rack. On the interior of the switchgear cabinet rack, the profile sides of the frame legs, which extend vertically in respect to each other, form fastening receivers extending over the entire length of the profile sides.
By means of transition sections, the profile sides form a dovetail groove, which is open toward the interior of the switchgear cabinet rack. It is possible to insert a dovetail strip into the dovetail groove, which is supported in the dovetail groove, as a fastening element. A fastening block is inserted in an inserting position into the dovetail groove and is then rotated by 90xc2x0 and brought into the fastening position. Although the fastening block is maintained in the fastening receiver, it can be continuously displaced in the fastening receiver.
It is one object of this invention to provide a device of the type discussed hereinabove, which has a fastening block, whereby simple fastening elements can be quickly and simply fixed in place on the frame leg and offer fastening possibilities for attachment elements in all directions.
This and other objects of this invention are achieved by a device for fastening attachment elements on a frame leg of a switchgear cabinet comprising fastening elements designed as fastening blocks, which are disposed against the profile sides of a frame leg, having two contact faces extending at right angles in respect to each other and are connected thereto. The contact faces of the fastening blocks make transitions into fastening faces which, when the fastening blocks have been attached to the frame leg, terminate flush with the additional profile sides of the frame leg. On their front faces extending vertically in respect to the longitudinal direction of the frame leg and on their fastening faces which are flush with the additional profile sides, the fastening blocks form fastening receivers designed as bores and/or threaded receivers.
The fastening block in accordance with this invention is simply inserted into the fastening receiver of the frame leg and connected to it. The fastening faces terminating flush with the additional profile sides provide connecting possibilities in two directions, which extend at right angles in respect to each other, without the attachment of attachment elements being hindered by the frame legs. A connecting possibility in a third direction is provided by the front faces of the fastening block, because the front faces extend vertically in respect to the longitudinal direction of the frame leg.
A positioning of the fastening blocks matched to the rows of fastening receivers formed by the profile sides of the frame legs is achieved whereby one of the contact faces is provided with shoulders, which can be introduced into fastening receivers of a profile side of the frame leg, and the other contact face can be screwed in place on the other profile side by means of a screw. In order to continue the grid of the system rows also with the fastening blocks, a further embodiment provides that the fastening faces of the fastening blocks form at least two bores and/or threaded receivers, which have a spacing in the longitudinal direction of the frame leg which corresponds to the grid dimensions of the system fastening receivers of the switchgear cabinet rack. The shoulders on a contact face permit the definite positioning in accordance with the grid dimensions of the system fastening receivers and do not interfere with the insertion of the fastening receivers of the frame leg.
In accordance with one embodiment of this invention, the screw-connection of the fastening block to the frame leg is achieved by the screw being inserted into a through-bore, which is offset in diameter and starts at the fastening face located on the parallel fastening face opposite the contact face, or the screw being inserted into slit-shaped recesses of the fastening faces and of a least one contact face, wherein the recesses form support strips for the screw head in the area of the contact face.
In accordance with another embodiment of this invention, the width of the recess in the fastening faces is matched to the diameter of the screw head of the screw, and the width of the recess in the contact face is matched to the diameter of the threaded portion of the screw. As a result, the screw-connection possibilities can still be further expanded in that both contact faces form a recess for a screw which only extends over a portion of the width of the contact faces and starts at the facing fastening faces.
In accordance with a further embodiment of this invention, the contact faces and the fastening faces make transitions into each other by means of transition sections extending parallel to each other. The fastening blocks have sufficient room in the fastening receiver of the frame leg and do not unnecessarily project from the frame leg into the interior of the switchgear cabinet rack.
In accordance with yet another embodiment of this invention, the profile sides of the frame leg are a part of a dovetail-shaped fastening receiver and, with the fastening block attached to the frame leg, the transition sections extend parallel to the groove bottom. As a result, the fastening blocks fastened on the frame legs can be additionally supported in the groove bottom of the dovetail groove.
The fastening blocks can be cost-effectively produced as simple injection-molded elements made of metal or plastic.